MUNICH – Patients with severe psoriasis have a twofold increased risk of developing new-onset diabetes based on a review of more than 4 million Danish children and adults, the first nationwide cohort to be evaluated for a link between the two diseases.
"Our results underline the importance of considering psoriatic patients as a high-risk population in terms of diabetes and cardiovascular risk," Mr. Usman Khalid said at the Annual Congress of the European Society of Cardiology. "Screening for diabetes and cardiovascular risk factors in patients with psoriasis is warranted," and follows existing guidelines for managing patients with psoriasis, said Mr. Khalid, a researcher in the cardiovascular research unit of Gentofte Hospital in Copenhagen.
The likely mechanism underlying the association is the inflammatory state of patients with psoriasis, he added.
"These observations are new, interesting, and important," commented Dr. Lars Rydén, professor of cardiology at the Karolinska Institute in Stockholm. Physicians should add "carefully looking for diabetes" to their existing routine screening in psoriasis patients, he said.
The study used Danish national population and patient records for more than 4.6 million Danish citizens aged 10 years or older from 1997 through the end of 2009. The researchers excluded the 97,000 people who had diabetes, psoriasis, or both at entry into the database, which left just more than 4.5 million people, of whom 52,613 developed new-onset psoriasis during follow-up, and 4,465,643 people without psoriasis who served as the reference population. The researchers defined severe psoriasis as a case that required hospitalization at least three times, or patients diagnosed with psoriatic arthritis. The cohort of children and adults with incidence psoriasis included 45,829 mild cases, and 6,784 severe cases.
The researchers tallied the number of people who developed new-onset diabetes, both among those who never had psoriasis during the study period, and among those who developed psoriasis. They identified new diabetes cases based on initiation of treatment with one or more glucose-lowering drugs. During follow-up, the number of new cases of diabetes was 3.67/1,000 person-years among those with no psoriasis, 6.93/1,000 patient-years among patients with mild psoriasis, and 9.65/1,000 patient-years among patients with severe psoriasis. The vast majority of the diabetes that developed was type 2.
Using adjustments that controlled for potential confounders at baseline, including age, sex, comorbidities, medications, and socioeconomic status, the researchers found that, compared with the people without psoriasis, those with mild psoriasis had a statistically significant 47% increased incidence of diabetes, and severe psoriasis linked with a statistically significant twofold increased risk for diabetes, Mr. Khalid reported. The median time from onset of psoriasis to the first treatment for diabetes was about 6 years.
The analysis notably focused on patients who developed diabetes following initial development of psoriasis, which provided insight into the sequence of the two diseases that had not been available in previously-reported studies, noted Dr. Ole Ahlehoff, a cardiology researcher at Gentofte Hospital and collaborator on the study.
"I suggest screening patients with psoriasis once a year for cardiovascular risk factors, including hypertension, dyslipidemia, lifestyle factors, and diabetes based on their glucose level," said Dr. Ahlehoff, who spoke about the research at a press conference. Medical groups have released guidelines that recommend annual risk assessment for patients with severe psoriasis, such as psoriatic arthritis, including the European League Against Arthritis (Ann. Rheum. Dis. 2010;69:325-31), and the Scottish Intercollegiate Guidelines Network.
Mr. Khalid and Dr. Ahlehoff said that they had no disclosures. Dr. Rydén had no relevant disclosures.